Lifting mechanism for traversing hoists



Dec. 29, 1931. G A. GRAB LIFT'TNG MECHANISM FOR TRAVERSING HOISTS 7 3Sheets-Slieet Original Filed July 23. 192'? //\/4/5/\/ TUK 7 7-7-UF /VEDec. 29, 1931. G. A. GRAB 1,838,939-

LIFTIGG MECHANISM FOR TRAVERSING HOISTS Original Filed July 23. 1927 3Sheets-Sheet 2 m-WW 4 7- 77:7 KNEW Dec. 29, 1931. 54 A. GRAB LIFTINGMECHANISM FOR TRAVERSING HOISTS 192'? 3 Sheets-Sheet 3 Original FiledJuly 23,

Patented Dec. 29, 1931 UNITED STATES PATENTOFFIICAE GUSTAV A. GRAB, OFPORTLAND, OREGON, ASS IGNOR, BY MESNE ASSIGNMENTS, 'I.0

WILLAMETTE-ERSTED COMPANY, OF PORTLAND, OREGON mrrme macnmisir roaTRAVERSING- nors'rs Substitute for application Serial No. 207,873, fllcdIuly 23, 1927. This application filed Kay 26, 1930.

' Serial No. 455,927. I

This application is substitute for application Serial Number 207,873filed July 23, 1927 and the invention relates enerally to traversinghoists, and particular y to a special form of lifting mechanism wherebyloads may be picked up or lowered.

The first object of this invention is to provide a special form oflifting mechanism for traversing hoists which can be operated from thehoist engine independently of any other duties which such engine isperforming.

The second object is to provide a dry transmission for the liftingmechanism to eliminate the undesirable scattering of oil over the lumberor other material being handled.

The third object is to provide an exceedingly quiet and smoothlyoperating lifting a mechanism which will require only a minimumapplication of hand power from the operator to control the lift which islocked in any osition it is moved by the operator.

The ourth object is to so construct the lift that the clearance betweenits upward and downward driving positions is'exceedingly snall, therebymaking large lever ratios possi le.

The fifth object is to so construct the drive that there will be nodanger from wearing flat spots on the friction element.

The sixth object is to provide a plurality of automatic stops for thelifting mechanism which will disengage same in either its upward ordownward limit of travel, without v load, and in its upward limit oftravel, with load.

The seventh object is'to combine the load stops to the load bindingmechanism.

These, and other objects, will become more apparent from thespecification following as illustrated in the accompanying drawings, inwhich:

Figure 1 is a side elevation of a traversing hoist. Figure 2 is adiagrammatic .view showing the friction gearing in a load liftingposition. Figure 3 is "similar to Figure 2 but showing the gears in alowering position. Figure 4 is similar to Figures 2 and3 showing theparts in a neutral position. Figure 5 is a perspective viewa'of thehoist frame and the parts related to this invention. Figure 6 is anenlarged side elevation of the combined load stop and load bindingmechanism. Figure 7 is a transverse section taken along the line 77 inFigure 5 Figure 8 is a broken section taken along the line 8-8 in Figure7. Figure 9 is a horizontal section taken along the line 9-9 in Figure7. A

Similar numbers of reference refer to similar parts throughout theseveral views.

Referring in detail to the drawings, there is illustrated the frame of atraversing hoist including the corner posts 11 which carry the spindles12 of the wheels 13, and also the cross ties 1 f which join the posts 11laterally, while the cross ties 15, 16 and 17 .join the members 11longitudinally. There is also in-' dicated the propeller shaft 18 of amotor 18A. The propeller shaft 18 is joined by a "flexible coupling 19to the extension shaft 20, which passes through the housing 21 which, inturn, extends laterally across the hoist and is secured to the members15 by means of the bolts 22. It will be understood that the shaft 18 ispreferably at the forward end of the motor 18-A from whose rearward endthe hoist may be propelled along the ground in any desired manner.

On the shaft 20 is keyed the flanged cent'er 23 of the friction wheel24, which is clamped to the member'23 by the bolts 25 and the ring 26.The under side of the member 21 is open and is provided with thedownwardly projecting arms 27, between which is hinged the rockableframe 28 which is mounted on the shaft 29 whose ends are supported bythe eccentric bushings 30 in the arms 27. The shaft 29 is pinned to bothof the eccentric bushings 30 can be held in any desired position.

In the rockable frame 28 are mounted the shafts 32 and 33 on which arekeyed the gears 34 and 35 which mesh at all times. On the shafts 32 and33 are also secured the friction wheels 36 and 37 which, mainly forthepurpose of assisting in better showing their acttion, are shown ofunequal size.

It will be noted in Figures 2, 3, 4 and 7 that either of the wheels 36or 37 can be brought into engagement with the wheel 24, or both may beheld out of engagement therewith. In order to rock the frame 28 andproduce the desired kind and degree of engagement between the variousfriction wheels'there is provided a rotatable shaft 38 having onopposite ends thereof the oppositely threaded portions 39 which arecarried by the wrist pins 40 in the arm 41 and the wrist pin 42 in thebracket 43. The shaft 38 is rotated by means of a lever 44 which issecurely mounted thereon and to whose endis attached a connecting rod 45whose opposite end is attached to a lever 46 on the rock shaft 47 whichis operated by a hand lever 48 whose quadrant 49 is provided with asingle notch 50 which corresponds with the neutral position in which thefriction wheels are held out of engagement.

It canbe seen that by making-the pitch of the threads 39 on the shaft 38suitable for the purpose that the friction applying mechanism is selflocking and that a great deal of pressure can be applied to the frictionsurfaces without the exertion of much manual efl'ort.

On account of this construction it is necessary that the total of theclearances between the wheel 24 and the wheels 36 and 37 shall be keptto the minimum, which is rendered easily possible by the eccentricmounting for the shaft 29.

On the shaft 33 are mounted the sprockets 51 whose chains 52 pass aroundthe sprockets 53 on the longitudinal shafts 54, which are mounted in thebrackets 55 on the ties 16. The shafts ,54 are provided with threadedends 56 on which are placed the traveling nuts 57. From each nut 57extend the side links 58 which are attached to the bell crank lever 59on the bracket 60. The bell crank lever 59, in turn, operates thelifting rod 61 which operates the load lifting mechanism- 62, which isfully described in my Patent 1,734,330, issued November 5, 1929.

In order to prevent the nuts 57 from turn mg there is provided for eachof same a horizontal guide 63. Astarting crank 64 is also provided onthe forward tie 14 for the purpose of applying rotary motion tothe shaft20 as when starting. The usual spring 65,

as is common witlieranks of this nature, is

also employed.

Alongside of one shaft 54 is mounted a slidable rod 66 whose forward endis supported in the arm 57A which projects from a. trunnion of a nut 57.The rod 66 carries in front of the arm 57A a pair of nuts 68 whichengage the arm 57A when the load l1 fting mechanism is in its lowermostposition. The rearward end of the rod 66 passes through the arm 67,which is keyed to the shaft 68A which, in turn, journals in the bearing69. The rod 66 is provided with a threaded end 70 which extends into theslotted coupling 71 to which motion can be supplied by the lever 72which is pivotally mounted on the pin 73. The lever 72 is, in turn,adapted to be rocked by the connecting rod 74 .which is attached to thelever 75 on the shaft 47.

On the threaded portion 70 of the rod 66 are placed the nuts 76 and onthe opposite side of the arm 67 is secured the adjustable stop 77.

On the shaft 68--A are mounted the downturned arms 78 on whose lowerends are secured the channel bar 79 which is urged downwardly by thesprings 80 whose upper ends bear against the ties 15.

The operation of the device is as follows: When it is desired to pick upa load of lumber the carrier is driven straddle the pile, as is a matterof common knowledge, and the particular load engaging mechanism employedis operated so that the load will be engaged. It is assumed that theengine-is running and the lever 48 is now moved away from its neutralposition so as to rock the shaft 47 in a manner that the frame 28 willswing into the position shown in Figure 7,

wherein the wheel 37 engages the wheel 24. The wheel 36 is now beingidly driven and is not transmitting any power whatsoever; whereas thewheel 37 is rotating the shafts 54 in a manner to lift the load. I

When the load is raised sufiiciently high the operator merely moves hislever 48 to the neutral position where it is held by the notch 50. Thenotch 50 has, in reality, a double functionfirst the preventing of thelever 48 from being carried away from its neutral position by gravityand vibration and second that of insuring that the wheels 36 and 37willbe held completely out of engagement when in the neutral position.

If, for any reason, the operator should fail to move the lever 48manually when a load is moved to the uppermost height, namely when itcomes in contact with the bar 7 9, then the first thing which transpiresis that the springs 80 are put in compression, thereby causing the bar79 to serve as a load binder.

However, as the bar 79 moves upwardly it 1 rocks the shaft 68A andcauses the arm 67 to engage the nuts 76 and ultimately, through thelever 72 and the parts 74 and 75, causes the hand lever 48 to move toits neutral position.

If it is desired to lower a load the hand lever 48 is moved in theopposite direction from that above described, causing the wheel 36 to bebrought into engagement with the wheel 24, in which case the wheel 36acts as an idler, and since this is a lowering operation it has, inreality, very little, if any, driving action to perform. i

In case the operator fails to disengage his friction wheels manually onthe downward travelthen the arm 5 7A will engage the nuts 68 andautomatically stop the mechanism. The same is true of the upwardunloaded position of travel, in which case the arm 67 engages the stop77 and automatically shifts the lever 48 to the neutral position.

Again, owing to the fact that cylindrical friction units are employedinstead of conical it will be almost impossible to wear fiat spotsthereon, since the friction element which is most easily worn, is therotating member, whereas the others aremetal.

By this constructionit is possible to secure a very smooth operation forthe hoist, which greatly adds to its life, as well as decreases itsmaintenance cost.

Where other load binders are required in front of or behind the oneillustrated these can consist of spring urged bars similar to the bar 79against which the load can be raised and thereby securely bound.

I am aware that many forms of traversing hoists have been constructed inthe past; it is therefore not my intention to cover such devicesbroadly, but I do intend to cover all such forms and modificationsthereof as fall fairly within the appended claims.

I claim:

1. Ina traversing hoist, the combination of a wheeled frame; a motormounted on said frame having a load lifting power take-off at one end ofits crank shaft; with a load lifting transmission taking its powerdirectly from said engine; a sprocket operated load lifting shaft memberat each side of said frame; a reversible shaft frietion'ally driven fromsaid load lifting power takeoff; sprockets on said reversible shaft; andchains connecting said sprockets with said load lifting sprockets.

2. In a traversing hoist, the combination of a wheeled frame having aload lifting mechanism mounted thereon and having a power unit mountedon said frame, said power unit having its load lifting takeoff at theforward end thereof; driving connections between said propelling takeoffand said wheeled frame, a friction wheel on said load lifting takeoff; arockable frame mounted adjacent to said friction wheel; a pair offriction wheels mounted on said rockable frame having gears thereon fordriving same in opposite directions but having their friction facesseparated from each other; means for moving said rockable frame so thateither or neither of said geared friction wheels engage the frictionwheel on the load lifting takeoff: and driving connections between oneof said geared friction wheels and said load lifting mechanism.

3. In a traversing hoist, the combination ofa vehicle frame includingload-lifting members with an operating motor mounted on said hoist andhaving a load lifting transmission mounted in front of'the cranking endofthe motor, said transmission comprising a transmission frame; anextension for the crank shaft of the motor journaling in said frame; afriction wheel on said extension shaft; a rockable frame hinged to saidtransmission frame; a pair of meshing gears mounted on said rockerframe, one of said gears delivering power to the load lifting members ofthe hoist, both of said gears having friction wheels attached theretobut not contacting with each other; and screw means for operating saidrocker frame in a manner that either or neither of said gear frictionwheels will engage the friction wheel on said extension shaft.

4. A traversing hoist including a hoist propelling shaft with an enginefor driving same and having load lifting mechanisms mounted thereon anda load lifting transmission operable independently of the hoistpropelling transmission, said load lifting transmission consisting of afriction wheel driven directly by the engine; a pair of friction wheelsrockably mounted alongside of said first mentioned wheel; means forrocking said friction wheels in a manner that either or neither of sameare brought into engagement with said engine driven friction wheel; apair of meshing gears attached to said rockable friction wheels fordriving same in opposite directions; and chain and sprocket membersbetween one' of said rockable gears and the lifting mechanism of thehoist.

GUSTAV A. GRAB.

